A One-pot Approach to Ethyl 1,4,5-Triaryl-1<i>H</i>-pyrazole-3-carboxylates via an Improved Claisen Condensation-Knorr Reaction Sequence
作者:Jiaojiao Zhai、Chunhui Gu、Jianan Jiang、Shunli Zhang、Daohua Liao、Lei Wang、Dunru Zhu、Yafei Ji
DOI:10.1002/cjoc.201300776
日期:2013.12
one‐pot approach to ethyl 1,4,5‐triaryl‐1H‐pyrazole‐3‐carboxylates has been developed in moderate to high yields. The tert‐BuOLi‐mediated Claisen condensation of 1,2‐diarylethanones and ethyl oxalyl chloride efficiently provided the enolized lithium salts of ethyl 2,4‐dioxo‐3,4‐diarylbutanoates, which in situ reacted with arylhydrazine hydrochlorides via a hydrochloric acid‐promoted Knorr reaction to produce
已经开发了一种单罐方法来中,高产率地生产1,4,5-三芳基-1 H-吡唑-3-羧酸乙酯。的叔1,2- diarylethanones和-BuOLi介导的克莱森缩合乙基草酰氯有效地提供乙基2,4-二氧代-3,4- diarylbutanoates,其在原位与芳基肼盐酸盐通过盐酸的酸反应的烯醇化锂盐促进了克诺尔反应,生成了精美的三芳基吡唑-3-羧酸酯。该程序保证可以方便地访问这个高度拥挤的药物发现框架。